About System Prompt Builder
Build a system prompt from JSON fields or a one-line goal.
How to use it
- Paste input (or set the options).
- Click Build, or press ⌘/Ctrl + Enter.
- Copy the result.
Tool
Build a system prompt from JSON fields or a one-line goal.
Your data stays in your browser. Nothing is uploaded to our servers.
Build a system prompt from JSON fields or a one-line goal.
AI
Estimate USD cost from input and output token counts.
AI
Estimate token count for a prompt without sending it to an API.
AI
Turn JSON context into a readable user prompt with fenced blocks.
AI
Normalize spacing and paragraph breaks in LLM prompts.